US1507379A - compositions - Google Patents

Description

-. COMPOSITIONS,

COATING R PLASTIC.

b\l% l 'atented Sept. 2, 1924. 0

UNITED STATES WILLIAM HOSKINS, OF CHICAGO, ILLINOIS, ASSIGNOR T0 ECONOMY FUSE 6'0 MANU- FACTU ANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

PLASTIC.

No Drawing.

T 0 all it may concern Be it known that 1, WILLIAM HOSKINS, a

. citizen of the United States, residing at 111 West Monroe Street, Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Plastics, of which the following is a specification.

In accordance with the present invention a cement is prepared by admixing with an inert material a primary binding constituent which will cause the cement to set when treated with a solution of phosphoric acid, this binding material being an aluminate of a metal of the alkali or alkaline earth groups. The primary bindin constituent of the oement may b prepaggiby mtimatelv admixing alumina or alumi 1 d d m eor car )01'18 o 0 pren in equimolecular proportions or in excess, the excess of the calcined alumina being, in the latter case, incorporated in the cement as a part of the inert material or filler. The temperature of calcining should be sufliciently high to cause reaction, but may in general be not higher than intering tem erature. With higher temperatures care must be taken to avoid decomposition of the aluminate. A temperature of approximately 1000 C. (and below 1300 C.) is satisfactory for the production of the aluminate in substantially all cases. Thus 100 parts of calcium carbonate and 140 parts of aluminum hydroxide (equimolecular proportions) may be calcined at 10001100 C. until no more CO is evolved, the resulting al minate materialbeing a bindin mater'lal suitable m e in Application filed March 17, 1921. Serial No. 452,953.

for example, of sufficient fineness to pass inert or non-Bonding Ell alumina and the like, the propo 1OI1 0 Binding material being not less than 2% of the whole.

The ro ortio f binder resent influences therata thegreaterje pro,- por -1OI1 o f bind.er the.mone rapid the set. In

gem-175171501 technical purposes, 1t"'i"' preferred that the ro ortio'n of binder; do not exceed 10%, as W1 more an of the alumina 'e in er the rate of setting is too rapid for general technical use. With 2% of the aluminate binder in the mixture a temperature above ordinary atmospheric temperature is necessary to produce a set in a reasonable time, a temperature of 100150 C. being preferred. With 34% of aluminate binder, say, calcium aluminate, a period of above 30 days is required for setting at ordinary temperatures, the final set not be reached for 2 to 3 months; at 110115 from 12-24 hours is required, and at 140- 150 C. 2 to 3 hours is sufiicient for the set although a longer period, say, 10 to 12 hours or more is preferred. In very rapidly setting cements, such as dental s, theproportion of binder emp oye exceeds 10%, and may be as high as 65-75%.

A ma 'al may be employed as a fillerand any suitable inert pigment materials may be used for coloring the cement. The tensile strength of the material is affected by the character of the filler, a higher tensile strength being secured with materials and 7 parts of calcium car na e. ca cinmg of sharply angular character, particularly e excess of alumina in the ca cine mixture is incorporated in the cement as a part of the filler.

Anip xide, hydrate or carbonate of any metal of the alkali an a a me earth groups for thewamfiifitrgzbonate tensile strength.

in the above example in w o e or 1n par d1 m carbonate. t.

'e 0., may uemp oye t is preferred that the constituents of the mixture to be calcined be very finely gound er, such as silica the desired pro ertie final molded article, such as arium sulfate asbestos fiber owder c a a umina.

o irne sum an ma neslte etc. 1 ers 5 such as calcmed'alumma and hydraulic gypsum inffiience the rate of set oy reason of eir facility of combination with water, thereby increasing the concentration of the setting liquid. They are, however, inert in that they do not otherwise appear to partake in the setting reaction. The greater the proportion of such fillers, other factors being the same, the slower the set, in the measure that the concentration of the setting liquid 16 is increased by the dehydrating action of the filler constituent. With increase in concentration an increase in the tensile strength of the molded article is found.

, The setting liquid to be admixed with the 0 cement to produce the plastic material is a solmjoF of phosphoric acid. which may, if es1re con aln 10s 1a es. A liquid suitable for use in commerclal practice may be prepared by mixing 308 parts by weight of 2 85% hos )horic acid. 60 parts by weight of zinc oxide and parts by weight of water. lhe proportions of the constituents may be varied and the zinc oxide may be omitted entirely or may be partially or completely 30 replaced by other oxides or phosphates, for

example, aluminum oxide, sodium hydroxide. sodium ahos hate. etc. lime, in the manufacture of synthetic porcelains or dental cements, the zinc oxide or any substitute 36 therefor, may be omitted. the liquid then containing phos horic acid and water. The concentration omthe liquid influences the rate of setting and the tensile strength of the molded article, as with concentrations of phosphoric acid above that set forth supra, the filler remaining un changed. the rate of setting is decreased and the tensile strength increased. The concentration of phosphoric acid may be varied by varying the relative proportions of phos phoric acid and water in the mixture. or. as hereinbefore set forth, it may also be varied by the use of dehydrating fillers. that is. fillers capable of chemically combining with water and thereby increasing the concentra- -tion of the phosphoric acid. The proportion of liquid to cement should be suflicient to cause at least a wetting of the particles of the cement by the liquid. In the case of com 1 dits. intended tomenfild'eflffdn exam e. 1111 .er pressure in ms, the ro or, tifiiigui hogld not be so grea% ma e tie mass stickly or tacky when compressed. Thus, with a cement containing about 3% of binder, that is, calcium aluminate, and with quartz and alumina as fillers the proportion of liquid of the specific composition above set forth may suitably be about parts to 100 parts of cement (by 65 weight).

which are employed in a highly fplastic state and contain large proportions o the binder, much larger proportions of the setting liquid may be used; for example, the setting liquid and cement may be in equal proportions by weight.

It is readily apparent that cements prepared in accordance with the present invention may be controlled within wide limits as to their behavior, particularly in setting. and that their physical character may be greatly varied. As an example of a cement which can be used for cold molding, I may prepare a mixture of one part ignited alumina and two parts of silica, preferably in the form of crushed quartz, and add to the mixture 3% of calcium aluminate binder, prepared as above set forth. The mixture, preferably finely ground to about 200 mesh or less and thoroughly mixed, is admixed with setting liquid, for example, of the proportions described above for use in commercial practice, the liquid and the cement being in the proportion of about 1 to 8 by weight. The mixture is plastic under pressure and 11121V b 6 molded into the desired for in a cold press under a suitable pressure, say 2 25 tons or hi her. When the mixture is fFesh itmency to stick to the dies. This tendency appears to disappear after the mixture has aged somewhat, say 12 hours or longer. The pressed article has sufiicient coherence to permit handling. At ordinary temperatures upwards of a month is required to cause it to set. By heating to 110 to 115 C. it may be caused to set in about 12 hours or more, a longer time being preferred. At a temperature of 140 to 150 an initial setting may be effected in one-half to one hour; a longer setting period, say 12-18 hours is preferred. The plastic mixture of cement and liquid may be molded for a considerable period after it has been admixed. provided it is kept at ordinary temperature or cooler. It molds well even after ten days to two weeks standing.

As has been set forth earlier in this specification, the filler constituents of the cement may be greatly varied. Thus, in the preceding example, the proportions of alumina to .silica may be one to four, the resulting molded article, after setting, having very nearly the same tensile strength and hardness as one prepared from a mixture of one part alumina and two parts silic In either case the final material has a tensile strength equal to or ment. u I: 0| 0 which the final article appears to be less hard than when silica is used in the filler.

S1l1' 'ca alone may likewise be employed. Either t e a umina or the silica, or both. may be replaoedi whole or in other exceeding that of fillers, such as crushed glass, asbestos fiber. With cements for dental use dead burnt or hy raulic gypsum, dead burnt u. UUMIUSIIIUNS,

COATING R PLASTIC.

magliesite, etc., the characteristics of these fillers having already been set forth. Organic fillers of an inert character, such as 's nd the like may e emp oye. 1th such fillers there is, however, a tendency to discoloration by carbonization when the final article is set withthe aid of heat. Pigment fillers may, of course, be employed as desired. If more rapid setting is desired, higher proportions of the binder may be used. Although in the exam le calcium aluminate is stated to be the indemny aluminate of an alkali or an alkali earth metal ma Y be employed, or mlxtures thereof may e used, as fully set forth earlier 1n the specification.

Where alumina is used in the filler, as in the previous instance, an excess of alumlna may be calcin sintemi me a or alkali n, me a co oun emp over to form the bin a 0 re Oma er thus formed admix with the remaining constituents of the cement, proper allowance being made for the excess of alumina present in the binder.

In the setting of the cement there is substan la y no con raction and consequently hard molded articles may be made therefrom dition without pressure, and is to set rapidly, higher proportions of binder and of setting liquid should be employed than in the case of commercial cement intended for molding. Thus, by using a cement contain- 70 in to of aluminatwinder and mixifigtmmliaiijqual proportion of setting liquid, a highly plastic material is obtained which, at ordinary temperatures, will set in five minutes or less. In the mixing of such a material it is advisable that artificial cooling be employed to retard setting. The plastic material may be readily molded into shape and set.

In such a cement translucency can be secured by use of crushed quartz or crushed lass as a filler. l lillfilliw gd t at the setting liquid contain no zinc 0Xl( eT'" zinc phosphate or other phosphates, but consgt solely of phosphoric acid and Water.

For the formation of electric heatlng bodies, a suitableheatangelemantm ybe mbedde i i n-.thewcement, and secured toti ininals which may, if desired, likewise be embedded in the cement. The hgating el ment may suitably be of nickel chromium alloy, nickel, iron, etc. Resistance bodies may be formed by incorporating conductive filler material, for example, a bite. 'ron 30 with great accuracy. As the temperature glinfi etc, in the cement. Sued a reslsfance required for setting is relatively low, metal inserts may be molded in the plastic without danger of loosening during setting and consequently are very firmly held. Molded article's prepared from the cement may be given an impervious surface finish by impregnation with parafiine wax, carnauba wax, asphaltic and bituminous material, fats, and the like. This may suitably be 40 eifected by immersing the articles in the nielgd wax. By impregnation of the molde art1c e with hard waxes of the character of rna b wa their elasticity and resiliency may fie increased. Where highly elas- 45 tic or resilient molded articles are desired, a suitable filler should likewise be selected; for example, crushed glass.

In connection with the molding of commercial articles I have found it advanta- 50 geous to admix a small proportion, say M; to

3% of light Hmm'gam- 3gil for example kerosene. wlti e emen ne r cen ias been found to be a satlsfactory proportion. The presence of this small proportion of lubricant oil appears to have the effect of retarding setltling when admixed Wit-l; tge setting iqui prior to com o t e article in molding. When the article is comressed, the lubricant oil appears to be 69 orced out, lubricating the surfaces of the die and preventing sticking thereto. The set of the molded article appears to be in no way affected.

For special uses in which the cement is to be molded or shaped in a highly plastic conmay be foimth terminals partially embedded in the mass and may be provided with insulation formed of the cement, the whole being set simultaneously.

The ter nfisinlarinallas used herein designates a superficial fusion of the particles of the material and may or may not be accompanied by agglomeration. The term alkali forming metals, as used herein, designates the metals of the group including the alkali and alkaline earth metals.

claim:

1. A cement capable of setting with a solution of phosphoric acid and adapted for press molding. said cement comprising a filler and from 2 to 10% of calcium alumina e as its effective bonding constituent.

2. A cement capable of setting with a solution of phosphoric acid and comprising a filler includ'nv ilica and from 2 to 10% of an aluminate of an alkalj forming metal as its e co We on mg constituen 3. A cement capable of setting with a solution of phosphoric acid and comprising a filler including silica and from 2 to 106% of calcium aluminate as its effective bonding agent.

4. A cement capable of setting with a solution of phosphoric acid and comprising a filler including silica, an inert material capable of combining with water and an aluminate of an alkali forming metal.

5. A cement capable of setting with a solution of phosphoric acid and comprising a filler including silica, a dehydrating filler and from 2 to 10% of an aluminate of an alkali forming metal as its effective bonding constituent.

6. A cement capable of setting with a solution of phosphoric acid and comprising a filler including silica, a dehydrating inert material and from 2 to 10% of calcium aluminate as its effective bonding constituent.

7. A cement capable of setting with a solution of phosphoric acid and comprising a filler including silica, alumina and an aluminate of an alkali forming metal.

8. A cement capable of setting with a solution of phosphoric acid and comprisin a filler containing one part of alumina an two parts of crushed quartz and from 2 to 10% of an aluminate of an alkali forming metal.

9. A cement capable of setting with a solution of phosphoric acid and comprising a filler containing one part of alumina and two parts of crushed quartz, and 3 to 4% calcium aluminate.

10. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing as a primary binding constituent an aluminate of an alkali forming metal, a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufficient to wet the cement.

11. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing calcium aluminate as a primary binding constituent, a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufiicient to wet the cement.

12. The method of preparing a plastic mas capable of being molded under pressure which comprises admixing with a cement containing from 2 to 10% of calcium aluminate as a primary binding constituent a setting liquid comprising phosphoric aci and phosphates, the proportion of the liquid being at least sufiicient to wet the cement.

13. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing an aluminate of an alkali forming metal as a primary binding constituent and an inert filler compound capable of combining with water, a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufficient to wet the cement.

14. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing an aluminate of an alkali forming metal as a primary bindin constituent and an inert filler capable 0 combining with phosphoric acid, a setting liquid comprising phosphoric acid, the proportion of the latter being from 2 to 10%.

15. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing from 2 to 10% of an aluminate of an alkali forming metal and an inert filler including alumina, a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufiicient to wet the cement.

16. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing from 2 to 10% of an aluminate of an alkali forming metal as a primary binding constituent and an inert filler including asbestos, a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufiicient to wet the cement.

17. The method of preparing a plastic mass capable of being molded under pressure whlch comprises admixing with a cement containing an aluminate of an alkali forming metal as a primary binding constituent and an inert filler including a material capable of combining with water, a setting liquid comprising phosphoric acid, the proportion of the latter being at least suflicient to wet the cement, the proportion of the filler material capable of combining with water being selected to control the rate of set by varying the concentration of the setting liquid.

18. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing an aluminate of an alkali forming metal as a primary binding constituent and an inert filler including a material capable of combining with ph m7 horic time comprising phosphoric acid, the proportion of the latter being at least suflicient to wet the cement and the proportion of the filler material capable of combining with phosphoric acid being selected to control the rate of set by varying the concentration of the setting liquid.

19. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing from 2 to 10% of an aluminate of an alkali forming metal as a primary binding constituent and an inert filler containing 20 to 331% of alumina. a setting liquid comprising phosphoric acid, the proportion of the latter being at least sufiicient to wet the cement.

20. The method of preparing a plastic mass capable of being molded under pressure whlch comprises admixing with a cement containing 2 to 10% of an aluminate of an alkali forming metal as a primary 6. COMPOSITIONS,

COATING R PLASTIC.

binding constituent and an inert filler containing 335% of alumina, a setting liquid comprlsing phosphoric acid, the proportion of the latter being at least sufiicient to wet the cement.

21. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing with a cement containing an aluminate of an alkali forming metal as a primary binding constituent, a setting liquid comprising ph0sphoric acid and zinc phosphate in proportion at least sufiicient to wet the cement.

22. The method of pre aring a plastic mass capable of being mo ded under pressure which comprises admixing 100 parts of a cement containing about 3% of calcium aluminate and an inert filler containing one part of alumina to two parts of silica with parts of a setting 1i u1d containing phosphoric acid and zinc p osphate.

23. The method of preparing a plastic mass capable of being molded under pressure which comprises admixing a cement containing from 2 to 10% of an aluminate of an alkali forming metal as a primary binding constituent, a setting liquid comprising phosphoric acid in proportion at least sufficient to wet the cement and a small proportion of a light lubricating oil.

24. The met od of preparing a plastic mass capable of being molded under pressure which comprises admixing a cement containing from 2 to 10% of an aluminate of an alkali forming metal, a setting liquid comprising phosphoric acid in proportion at least suflicient to wet the cement and about 1% of kerosene.

25. A moldable, setting plastic mass comprising a filler, an aluminate of an alkali formingmetal, plfis'ph dric acid and water.

26. A moldable, setting plastlc mass comprising a filler, at least 2% of calcium aluminate, phosphoric acid and wa er. 27. A moldable, setting plastic mass comprising a filler including a substance capable of combining with water, at least 2% of an aluminate of an alkali forming metal, ph0sphoric acid and water.

28. A moldable, setting plastic mass comprising a. filler including a substance capable of combining with water, about 3% of calcium aluminate, phosphoric acid and water.

29. A moldable, setting plastic mass comprising a filler including alumina, at least 2% of an aluminate of an alkali forming metal, phosphoric acid and water.

30. A moldable, setting plastic mass comprising a filler including silica and alumina, at least 2% of an aluminate of an alkali forming metal,'phosphoric acid and water.

31. A moldable, setting plastic mass comprising a filler including silica and alumina, from 2 to 10% of calcium aluminate, phosphoric acid and water.

32. A moldable plastic mass including a filler, at least 2% of an aluminate of an alkali forming metal, a small proportion of a light lubricating oil, phosphoric acid and water.

WILLIAM HOSKINS.